Radio receivers which scan through a predetermined band of the radio spectrum, in a station-seeking mode, must independently detect whether the currently tuned frequency is the central frequency of the transmitting station and whether this transmitter provides a signal whose strength is sufficient, i.e. whose strength exceeds a predetermined threshold value. Once these two conditions are satisfied, the radio generates a "stop" signal which terminates the station-seeking mode, i.e. keeps the tuning circuit set to the frequency which provided the sufficiently strong signal.